Conventional charge generating dispersions typically include a charge generating material, a binder, and a solvent. As the binder, polyvinyl butyral resins such as the BUTVAR.RTM. resins may be used. Polyvinyl butyral resins are preferred materials for the binder since they yield robust charge generating dispersions with excellent coating quality and long pot life. However, the present inventors are aware that the use of polyvinyl butyral resins for the binder in a charge generating layer can decrease the sensitivity of the resulting photoreceptor. Thus, there is a need, which the present invention addresses, for modified polyvinyl butyral resins that when employed as the binder in a charge generating layer enable an increase in photoreceptor sensitivity without sacrificing dispersion quality.
BUTVAR.RTM. resins are described in a brochure (35 pages; copyright date 1989) from Monsanto Chemical Company.
Photoreceptor coating compositions are disclosed in Nealey et al., U.S. Pat. No. 5,418,107; Stegbauer et al., U.S. Pat. No. 5,324,615; Nukada et al., U.S. Pat. No. 5,393,629; and Mayama et al., U.S. Pat. No. 5,418,099.